<?php

function update_prof($update_data){
    global $session_user_id;
    $update = array();
    array_walk($update_data, 'array_sanitize');
    
    foreach($update_data as $field=>$data) {
        $update[] = '`' . $field . '` = \'' . $data . '\'';
    }

    mysql_query("UPDATE `users` SET " . implode(', ', $update) . " WHERE `user_id` = $session_user_id");
}

function change_password($user_id, $password) {
    $user_id = (int)$user_id;
    $password = md5($password);
    
    mysql_query("UPDATE `users` SET `password` = '$password' WHERE `user_id` = $user_id");
}

function register_user($register_data) {
    array_walk($register_data, 'array_sanitize');
    $register_data['password'] = md5($register_data['password']);
    
    $fields =  '`' . implode('`, `', array_keys($register_data)) . '`';
    $data = '\'' . implode('\', \'', $register_data) . '\'';
    
    mysql_query("INSERT INTO `users` ($fields) VALUES ($data)");
}


function user_data($user_id){
    $data = array();
    $user_id = (int)$user_id;
    
    $func_num_args = func_num_args();
    $func_get_args = func_get_args();
    
    
    if($func_num_args > 1){
        unset($func_get_args[0]);
        $fields = '`' . implode('`, `', $func_get_args) . '`';
        $data = mysql_fetch_assoc(mysql_query("SELECT $fields FROM `users` WHERE `user_id` = $user_id"));
        
        return $data;
    }
   

}

function logged_in(){
    return (isset($_SESSION['user_id'])) ? true : false;
}

function user_exists($username){
    $username = sanitize($username);
    return (mysql_result(mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username'"), 0) == 1) ? true : false;
}
function email_exists($email){
    $email = sanitize($email);
    return (mysql_result(mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE  `email` = '$email'"), 0) == 1) ? true : false;
}

function user_id_from_username($username){
    $username = sanitize($username);
    return mysql_result(mysql_query("SELECT `user_id` FROM `users` WHERE `username` = '$username'"), 0, 'user_id');
}

function login($username, $password) {
    $user_id = user_id_from_username($username);
    
    $username = sanitize($username);
    $password = md5($password);
    
    return(mysql_result(mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username' AND `password` = '$password'"), 0) == 1) ? $user_id : false;
}
?>